Hard disk drives (“HDDs”) may have exacting height constraints that limit the axial space in designs including fluid dynamic bearing (“FDB”) motors. The limited axial space in such designs may provide FDB motors with insufficient journal bearing span, leading to reduced angular stiffness. Because angular stiffness is the mathematical product of linear stiffness (e.g., radial stiffness in the journal bearing and axial stiffness in the thrust bearing) and moment arm length (e.g., journal bearing span and thrust bearing diameter), larger diameter thrust bearings may increase the moment arm length, thereby increasing angular stiffness in cases where it is difficult to increase journal bearing span. However, larger diameter thrust bearings consume more power, leading to less power efficiency.